Field observations on conditions condusive to the contamination of groundnuts with the mould Aspergillis flavus Link ex Fries

No Abstrac

GENERATION AND DETECTION OF THE POLARIZATION OF MULTI-GEV PHOTONS BY USE OF TWO DIAMOND CRYSTALS

Abstract Presented are experimental results for the difference in pair production probability (the asymmetry) for 5–150 GeV photons polarized parallel and perpendicular to a (110) plane in a 1.5 mm thick diamond 〈100〉 crystal. The photons are produced by interaction of 150 GeV electrons with an aligned diamond 〈100〉 crystal of 0.5 mm thickness. A significant asymmetry is found over the whole energy range, which corresponds to a high degree of linear polarization of the photons as well as a difference in the refractive index. This proof-of-principle result gives the possibility of producing high energy photons with circular polarization by use of a crystal. This might open for several opportunities in high energy physics like for instance the investigation of the contribution of the gluons to the spin of the nucleon

Comprehensive study of the reactions induced by 12C on 103Rh up to 33 MeV/nucleon

Abstract Fifty-three excitation functions for the production of radioactive residues in the interaction of 12C with 103Rh have been measured from the Coulomb barrier up to 400 MeV by means of the activation technique. These excitation functions have been analyzed considering complete fusion, incomplete fusion of 8Be and α-particle fragments and, above about 200 MeV, the transfer of either one proton or one neutron from 12C to 103Rh. The emission of pre-equilibrium particles during the thermalization of the excited composite nuclei formed in all these processes and, in the case of 8Be and α incomplete fusion, also the re-emission of α-particles after a mean-field interaction or a few interactions with the target nucleons have been taken into account

CONSTRUCTION AND TEST OF A CHANNELING-RADIATION SOURCE AT THE NEW DARMSTADT SUPERCONDUCTING ELECTRON ACCELERATOR

A source to produce channeling radiation has been set up immediately behind the injector of the new superconducting electron accelerator, which has gone into operation this summer. The electron beam energy at that stage of the machine can be varied between 3 and 10 MeV and the low value for its divergence (0.041-0.015 mrad) is suited to create monoenergetic, polarized photons of high intensity in the keV-region. It is projected that an electron beam of 20 µ A and 10 MeV hitting a Si crystal produces a photon intensity of 1010 - 1011 photons/s into 1 mrad solid angle with a band width of Ɗ/E=0.1 at an energy of about 45 keV. The first crystals under investigation will be a Si (111) and a diamond (110) crystal